DE10022982A1 - Semiconductor component and method for its production - Google Patents

Abstract

A semiconductor device with a semiconductor chip is mounted on a resin substrate via an underfill resin in a flip-chip manner. In this semiconductor device, fillets formed on the side end surfaces of the semiconductor chip by injecting the underfill resin have a length greater than the distance from the surface of the resin substrate to the back of the semiconductor chip. As a result, the warpage of the insulating substrate when the underfill resin is hardened between the semiconductor chip and the insulating substrate is reduced, thereby preventing the underfill resin from peeling off.

Description

The invention relates to a semiconductor component and a Process for its manufacture. In particular, the Invention a semiconductor device with one on it Printed circuit board mounted in a flip-chip manner and a process for its manufacture.

Conventionally, a semiconductor device with a on its printed circuit board (PWB = printed wiring board) Known flip-chip mounted semiconductor chip.

Fig. 1 is a sectional view of a conventional semiconductor device of this type. As shown in Fig. 1, the semiconductor device 1 has an insulating substrate (PWB) 2 which is made of a resin such as polyimide. For reinforcement are on said insulating substrate 2, reinforcement plates 7, for example, glued, copper (Cu). A flip chip 4 with solder bumps 3 is mounted with the active side down on this insulating substrate 2 , in the area that is not covered by the reinforcement plates 7 . This solder bump 3 and the pre-soldering on the insulating substrate 2 are melted and connected to each other to produce an electrical connection between the flip chip 4 and the insulating substrate 2 .

For example, the distance between the flip chip 4 and the insulating substrate 2 is 120 microns, the pitch between rule's bumps are 240 microns, and the number of bumps is 3000. The chip 4 has a size of 13 mm square and a thickness of 0.68 mm.

In the manufacture of this semiconductor device 1 , a corresponding amount of epoxy type resin is injected as an under fill resin 5 into the solder joint area between the insulating substrate 2 and the flip chip 4 . The underfill resin 5 is then cured at an appropriate temperature, such as 150 ° C. By curing the overflows of the underfill resin 5, or the flutes 5 are a, formed so as to extend from the sides of the flip chip 4 on the insulating substrate. 2

After injecting the underfill resin 5 , a silver paste (Ag paste) with electrical conductivity is applied as an adhesive resin 6 a to the back (the upper surface) of the flip chip 4 . Here, an adhesive resin 6 b consisting of the same silver paste is also applied to the top of the reinforcing plates 7 , which are arranged on both sides of the insulating substrate 2 . Thereafter, a cover 8 made of Cu is placed on the rear side (the upper surface) of the flip chip 4 and the reinforcing plates 7 . Then the adhesive resins 6 a and 6 b are hardened in order to fix the cover 8 to the flip chip 4 and the reinforcing plates 7 .

After the cover 8 has been attached, solder balls 9 are mounted on the lower surface of the insulating substrate 2 , on which the flip chip 4 is not mounted, in order to obtain the semiconductor component 1 , which is a ball grid array package ( BGA) of the flip-chip type.

However, reliability tests, such as a temperature cycle test, which were carried out on the semiconductor component 1 , have shown that the insulating substrate 2 serving as an interposer has warped and voltages in the region between the flip chip 4 and the insulating substrate 2 , into which the underfill resin 5 is injected, has caused and thereby has facilitated the exfoliation of the underfill resin 5 .

In addition, the voltage applied to the underfill resin 5 voltages tended cracks c to produce the len of the Hohlkeh 5 a fen lau to the inner side of the insulating substrate. 2

The presence of such exfoliation and cracks create problems, such as one from an open one Failure resulting breakage. The exfoliation rate was after 300 cycles of the temperature cycle test at approximately 10% (5 out of 53 samples).

This leads to delamination of the underfill resin 5 when the flutes formed on the chip side 5a of the underfill resin 5 have a length smaller the fillets 5a are than the chip thickness, and below the chip. In such a case, the flip chip 4 and the insulating substrate 2 are subjected to larger voltages resulting from the difference in the coefficient of thermal expansion during the curing of the underfill resin 5 . As a result, the flip chip 4 and the insulating substrate 2 warp considerably.

Especially among the current semiconductor chips those with tightly packed wiring under Ver the use of flexible resin substrates. Conventional glass substrates that lack flexibility, cannot with such tightly packed wiring getting ready. That is why efforts are out of heat to get a grip on tension accompanying tension, indispensable.

An object of the present invention is to provide Provision of a semiconductor component and a process rens to its manufacture, which are prevented may that the insulating substrate when curing the Un Terfüllungseses between the semiconductor chip and the iso warping substrate warps so that exfoliation of the Underfill resin is prevented.

To achieve the above task, semiconductor construction element provided according to the present invention, comprising: a semiconductor chip attached to a Substrate over an underfill resin in a flip-chip manner is mounted, one on a side end surface of the Semiconductor chips by injecting the underfill har zes formed fillet has a length that is greater than the distance from the surface of the substrate to that Back of the semiconductor chip.

Because of the configuration described above, the fillet is le of a semiconductor device that one on a sub strat over an underfill resin in a flip-chip fashion mon Tected semiconductor chip includes on the side end surface of the semiconductor chip by injecting the underfill Formed resin, in a length that is greater is as the distance from the surface of the substrate to that Back of the semiconductor chip. This can prevent the isolating substrate during the hardening of the Un Terfüllungseses between the semiconductor chip and the iso warping substrate warping, causing the exfoliation of the Underfill resin is prevented.

In addition, the semiconductor device described above ment by a method of manufacturing a semiconductor Component manufactured according to the present invention become.  

The nature, principle and usefulness of the invention go from the following detailed description at Lek doors in conjunction with the accompanying drawings, in which the same parts have the same reference numbers or numbers Chen are designated.

In the accompanying drawings:

Fig. 1 is a sectional view of a conventional semiconductor device;

Fig. 2 is a sectional view, the approximate shape, the configuration of the semiconductor device according to a first exporting the present invention;

Figs. 3A to 3E process diagrams showing the method of manufacturing the semiconductor device of Fig. 2;

Fig. 4 of the semiconductor device according shows a sectional view tion general configura a second embodiment of the present invention;

Fig. 5 is a sectional view according to the approximate shape of a third exporting of the present invention showing the configuration of the semiconductor device;

. 6A and 6B are a plan view of a first example and a plan view of a second example, the showing in the semiconductor device of Figure 5 gebil Deten flutes. and

Fig. 7 is a sectional view showing the fillet formed in the semiconductor device of Fig. 5.

The following are preferred embodiments of the above lying invention with reference to the accompanying Described drawings.

Fig. 2 is a sectional view showing the configuration of the semiconductor device according to a first embodiment of the present invention. As shown in FIG. 2, the semiconductor device 10 has an insulating resin substrate (PWB) 11 made of, for example, polyimide. A semiconductor chip 12 of the flip-chip type is installed with the active side down on this insulating substrate 11 . In addition, a metal reinforcing frame 14 is arranged on the insulating substrate 11 so that it surrounds the semiconductor chip 12 . Then a cover 13 made of Cu is placed over the semiconductor chip 12 and the reinforcement frame 14 . The existing from the insulating substrate 11 , the semiconductor chip 12 , the reinforcing frame 14 and the lid 13 semiconductor device 10 has the appearance of a rectangular plate. The reinforcement frame 14 is arranged between the insulating sub strate 11 and the lid 13 to the insulating substrate 11 to protect the semiconductor chip 12 ken.

The insulating resin substrate 11 and the reinforcement frame 14 are bonded to each other by an adhesive resin 15 . The semiconductor chip 12 and the lid 13 are bonded together by an adhesive resin 16 . The cover 13 and the reinforcing frame 14 are bonded to one another by an adhesive resin 17 . These adhesive resins 15 , 16 and 17 use an Ag paste, for example of the silicon type, epoxy type or of the thermoplastic resin type.

The semiconductor chip 12 has solder bumps 18 and is mounted with the active side down on the insulating substrate 11 , the solder bumps 18 pointing downward. With this mounting, the solder bumps 18 on the semiconductor chip 12 and the pre-soldering on the insulating resin substrate 11 are melted and connected to each other to make an electrical connection between the semiconductor chip 12 and the resin substrate 11 .

A corresponding amount of epoxy type resin is injected as an underfill resin 19 into the solder joint area in which the solder bumps 18 are arranged between the semiconductor chip 12 and the insulating substrate 11 . The injection of the underfill resin 19 forms the overflows of the underfill resin 19 , or the fillets 20 , on the sides of the semiconductor chip 12 . The fillets 20 have in profile the shape of a generally right-angled triangle, with the line connecting an upper corner part 20 a and a lower corner part 20 b as the hypotenuse. At the upper corner part 20 a, the upper surface and a side end face of the semiconductor chip 12 meet one another. The lower corner part 20 b is the end point, which extends from the semiconductor chip 12 along the insulating substrate 11 . This right triangle has the base length L and the height H1.

The underfill resin 19 is adjusted with respect to the injection quantity, so that the distance from a lateral end surface of the semiconductor chip 12 to the lower corner part 20 b of the fillet 20 , or a fillet length L, is greater than the distance from the surface of the insulating substrate 11 to the top surface of the semiconductor chip 12 , or a chip height H1.

Here, the chip height H1 is the sum of the thickness of the semiconductor chip 12 and the thickness of a solder bump 18 , that is, the gap between the semiconductor chip 12 and the insulating resin substrate 11 .

In the present invention, the injection of the Un Interfilling resin controlled so that L <H1.

The injection of the underfill resin can also be controlled so that L <H2, where H2 is the height of the semiconductor chip 12 in the highest position in the middle of its upper surface from a non-warped area on the surface of the insulating substrate 11 near the Reinforcement frame 14 ; in other words, H2 is the maximum difference in elevation between the semiconductor chip 12 and the substrate 11 . Here L <H2.

In such ways, the fillet length L is adjusted according to the degree of deformation of the insulating resin substrate 11 .

For example, the insulating resin substrate 11 , the semiconductor chip 12 and the underfill resin 19 which follow the thermal expansion coefficient α (ppm / ° C). That is, the insulating resin substrate 11 has a coefficient of thermal expansion of α = 18. The semiconductor chip 12 has a thermal expansion coefficient of α = 3. The underfill resin 19 has a coefficient of thermal expansion of α = 20 to 32. In addition, the underfilling resin 19 has a viscosity of 13-40 (Pa.s).

A plurality of solder balls 21 are arranged on the lower surface of the insulating substrate 11 . These solder balls 21 are arranged over the entire surface of the insulating substrate 11 .

This semiconductor component 10 is configured so that the gap between the semiconductor chip 12 and the insulating resin substrate 11 is 120 μm, the pitch between contact bumps is 240 μm, the number of contact bumps is 3000, the chip size is 13 mm per side and the chip thickness is 0 , Is 68 mm.

Figs. 3A to 3E are sectional views showing the progressive sequence in the method of manufacturing the semiconductor device of FIG. 2. As shown in FIG. 3A, the rectangular resin substrate 11 is first prepared. This resin substrate 11 has a plurality of pads 22 arranged on its upper surface and a plurality of electrodes 23 arranged in advance on its lower surface. The contact points 22 and the electrodes 23 are electrically connected via wiring layers, not shown, within the resin substrate 11 to those which correspond to one another.

In addition, the reinforcing frame 14 , to which the cover 13 is later fixed, is bonded to the edges of the resin substrate 11 by the adhesive resin 15 . This reinforcing frame 14 has the function of providing space between the resin substrate 11 and the lid 13 for installing the semiconductor chip 12 .

Then, as shown in Figure 3B. Shown, the semiconductor chip 12 is placed with the active side down on the resin substrate 11, wherein the solder bumps are positioned at the contact points correspond to 22 18. After Plazie tion, the solder bumps 18 are melted and connected to the external electrodes 22 by melting.

As a result, as shown in FIG. 3C, the semiconductor chip 12 is mounted on the resin substrate 11 in a flip-chip manner. Flux cleaning is then performed.

As shown in FIG. 3D, in order to prevent the solder bumps 18 from peeling off, the underfill resin 19 having a flowability is then injected into the soldering joint region between the semiconductor chip 12 and the resin substrate 11 and applied to the substrate 11 . The injected underfill resin 19 spreads over the entire area of the semiconductor chip 12 , since the gap between the semiconductor chip 12 and the resin substrate 11 is extremely small.

Here, the underfill resin 19 is adjusted with respect to the injection quantity so that the fillets 20 have a fillet length L which is greater than the chip height H1, or the distance from the surface of the resin substrate 11 to the back of the semiconductor chip 12 , as in example 1 to 1.5 mm. In this case, the hollow length L is adjusted to approximately 1 mm with respect to the chip height H1 (120 μm + 0.68 mm = 0.8 mm).

Then, the underfill resin 19 is hardened (cured) at a corresponding temperature of, for example, 150 ° C.

Here, the chip connection area of the resin substrate 11 is deformed into a hill under the semiconductor chip 12 , the maximum warpage being of the order of 60 μm.

As shown in Fig. 3E, the adhesive resins 16 and 17 , each made of a silicon-type Ag paste with low elasticity, are on the upper surface (the side opposite to the side formed by the active element) of the semiconductor chip 12 and the upper surface of the reinforcement frame 14 is applied. After the cover 13 is placed over the semiconductor chip 12 and the reinforcing frame 14 , the entire housing is hardened out. This hardens the adhesive resins 16 and 17 to fix the lid 13 to the semiconductor chip 12 and the reinforcing frame 14 .

Thereafter, solder balls 21 are mounted on the lower surface of the resin substrate 11 on which the semiconductor chip 12 is not mounted to be connected to the external electrodes 23 . In this way, the semiconductor device 10 is obtained, which comprises a flip-chip type BGA package.

In short, the fillet length L of the underfill resin 19 formed on the sides of the semiconductor chip 12 can be made larger than the chip height H1 (or the chip height H2) in order to prevent the peeling of the underfill resin 19 injected between the semiconductor chip 12 and the resin substrate 11 . By avoiding the exfoliation can be prevented that the cracks c (see Fig. 1) from the end points of the fillets 20 , or the lower corner parts 20 b, run into the resin substrate 11 .

The semiconductor chip 12 described above was subjected to temperature cycle tests in which the chip was repeatedly alternately cooled to a room temperature and heated up to a predetermined high temperature. The result showed that the exfoliation rate after 300 cycles of the temperature cycle test was 0% (none of 97 samples). The reason for this is that the fillet length L executed larger than the chip height H1 allows a reduction (distribution) of the voltages applied to the semiconductor chip 12 and the resin substrate 11 .

As an alternative, the injection of the underfill resin 19 can be followed by the application of the adhesive resins 16 and 17 on the upper surface of the semiconductor chip 12 or the upper surface of the reinforcing frame 14 . In this case, the adhesive resins 15 , 16 and 17 can be cured together with the underfill resin 19 so that the sub fill resin 19 and the adhesive resins 15 , 16 and 17 are cured at the same time.

Consequently, although stresses are generated during the curing of the resins applied to the respective parts, the simultaneous hardening synchronizes the stress generation processes so that the stresses compensate each other. This can prevent local voltages from acting on the resin substrate 11 and the semiconductor chip 12 .

A description will now be given of a second embodiment of the present invention with reference to FIG. 4. Fig. 4 is a sectional view showing a semiconductor device 25 according to the second embodiment. In the semiconductor device 25 , as shown in FIG. 4, the underfill resin 19 injected into the solder connection area between the semiconductor chip 12 and the resin substrate 11 is hardened by using a mold not shown, so that the grooves 26 have a rectangular profile instead of one in the general right-angled triangle. The other configurations and functions are the same as those of the semiconductor device 10 (see FIG. 2).

Accordingly, the fillets 26 are formed into a thick wall surrounding the semiconductor chip 12 . As a result, the fillets 26 are shaped such that they are almost flush with the surface of the semiconductor chip 12 . In the present embodiment, the fillet length L (about 1 mm) is also larger than the chip height H1 (or the chip height H2) from the upper surface of the resin substrate 11 to the upper surface of the semiconductor chip 12 .

As discussed, the Hohlkeh according to the invention lenlänge L (the length of the overflows of the underfill resin 19, when the in the Lötverbindungsgebiet between the resin substrate 11 and the semiconductor chip 12 serves injected reinforcing resin from the sides of the semiconductor chip 12) adapted so that it is larger than the chip height, so that chip delamination and the like resulting from the warpage of the resin substrate 11 are avoided in the flip-chip type BGA semiconductor device 10 .

As a result, the stresses acting between the plural resins having different coefficients of thermal expansion can be distributed. This prevents the resin substrate 11 from warping on the occasion when the underfill resin 19 between the semiconductor chip 12 and the resin substrate 11 is cured, which makes it possible to prevent the underfill resin 19 from peeling and the cracks c in the resin substrate 11 .

Accordingly, the occurrence of the exfoliation and Prevents distortion, as in the conventional examples shown, whereby the semiconductor device with a Lötkon Clock bump structure in terms of productivity and reliability liquid can be improved.

This is particularly effective for the semiconductor chip 12 with tightly packed wiring using the flexible resin substrate 11 , which is currently the focus. That is, the semiconductor chip 12 with tightly packed wiring using the flexible resin substrate 11 contains up to about 3000 to 5000 pins, while a liquid crystal driver with a glass substrate contains about 40 to 50 pins. As for the chip size, the semiconductor chip 12 is approximately 13 to 17 mm square, whereas the liquid crystal driver is approximately 9 mm square. Since the tension is proportional to the area ratio, there is a large difference between the tension to be applied.

A description will now be given of a third embodiment of the present invention. Fig. 5 is a view Schnittan showing the configuration of the semiconductor device accelerator as the third embodiment of the present invention. 6A and 6B show. The semiconductor assembly in the element of Fig. 5 flutes formed. FIG. 6A is a top view of a first example, and FIG. 6B is a top view of a second example.

As shown in FIG. 5, a semiconductor device 30 is made hollow at the chip connection area of the insulating substrate 11 below the semiconductor chip 12 . Then, high-viscosity resin fillets 31 are formed in the generally rectangular-triangular parts between the sides of the semiconductor chip 12 and the surface of the substrate 11 . The other configurations are the same as those of the semiconductor device 10 (see FIG. 2). Here, the chip connection area where the semiconductor chip 12 and the substrate 11 face each other can be filled with an underfill resin having a lower coefficient of thermal expansion, instead of remaining hollow.

In this case, the fillets 31 are formed under the four corners of the semiconductor chip 12 except for the central parts of the four sides as shown in FIG. 6A, or they are formed under the central parts of the four sides of the semiconductor chip 12 except for the four corners as shown in Fig. 6B. In the present embodiment, the fillet length L has an arbitrary value, whereas those larger than the chip height H1 (or the chip height H2) enhance the effect as in the embodiment shown in FIG. 2.

In the present embodiment, the chip connection area of the resin substrate 11 under the semiconductor chip 12 is not covered with an underfill resin that generates stress upon curing, and even if it is covered with an underfill resin, the underfill resin has a lower coefficient of thermal expansion. Accordingly, no voltage is generated between the resin substrate 11 and the semiconductor chip 12 , or if so, only a low voltage is generated, whereby no warping or the like resulting from the generation of voltages is effected or a small effect is effected becomes.

For example, the fillets 31 and the underfill resin with a lower coefficient of thermal expansion, if injected, have the following coefficients of thermal expansion α (ppm / ° C). That is, the high viscosity resin for the fillets 31 has α = 10 and a viscosity of 100 (Pa.s). The underfill resin with a lower coefficient of thermal expansion has α = 7-10.

FIG. 7 is a sectional view showing the formation of the grooves in the semiconductor device of FIG. 5. As shown in FIG. 7, the fillets 31 are formed by dropping a high viscosity resin from a resin supply nozzle 32 onto the four corners or the four sides adjacent to the solder joint area. The Harzlieferdüse 32 is defined on the lateral end faces of the semiconductor chip 12 positio to be movable vertically along the side end surfaces of the semiconductor chips 12th

In a case where an underfill resin having a lower coefficient of thermal expansion is injected into the solder joint area between the resin substrate 11 and the semiconductor chip 12 , the underfill resin having a lower coefficient of thermal expansion can be injected through a vent hole into the fillets 31 made of high-viscosity resin.

As discussed, in the semiconductor device 30 shown in FIGS . 5-7, the chip connection area of the resin substrate 11 under the semiconductor chip 12 remains hollow (see FIG. 5) or is filled with the underfill resin having a lower coefficient of thermal expansion and is filled with the fillets 31 Use high viscosity resin. As a result, the chip connection area of the resin substrate 11 is not covered with an underfill resin that generates stress when hardened, or even when covered with some resin, the underfill resin has a lower coefficient of thermal expansion. This does not produce warping or the like resulting from the generation of stress, or it has a small effect.

Note that the present invention is not limited to one Semiconductor device with BGA structure is limited, such as in each of the embodiments described above, and themselves  likewise to a semiconductor component with a chip size Package structure (CSP) can be applied.

As has been described above, according to the present the invention, the semiconductor device, the one on a Substrate over an underfill resin in a flip-chip manner assembled semiconductor chip includes, fillets on which the side end faces of the semiconductor chip through the Injecting the underfill resin are formed. Here the length of the fillets is greater than the distance from the Surface of the substrate to the back of the semiconductor chips executed. This reduces warping of the isolie substrate when curing the underfill resin between the semiconductor chip and the insulating substrate, making it possible for the underfill to peel off prevent resin and cracks in the resin sub to avoid strat. Therefore, the semiconductor device with a solder bump structure in terms of productivity efficiency and reliability can be improved.

It has been described what is currently considered to be preferred embodiments of the invention is considered, however it is understood that various modifications are featured can be taken, and the appended claims are intended cover all such modifications that are in the actual Lichen thoughts and scope of the invention.

Claims (10)

1. A semiconductor device comprising:
a substrate;
a semiconductor chip mounted on the substrate; and
an underfill resin provided between the substrate and the semiconductor chip in a flip-chip manner, wherein a fillet formed on a side end surface of the semiconductor chip by injecting the underfill resin has a length of L toward the substrate surface, the length L being greater than the distance H1 between the upper surface of the semiconductor chip and the surface of the substrate. 2. The semiconductor device according to claim 1, wherein the length L the fillet is greater than the difference in elevation H2 between the highest position on the top surface of the semiconductor chip and a non-warped area the surface of the substrate. 3. A semiconductor device according to claim 1, wherein the sub strat is a resin substrate. 4. A semiconductor device according to claim 3, which comprises the following:
the substrate and the semiconductor chip together
connecting solder bump; and
a cover bonded by an adhesive resin both to the back of the semiconductor chip and to the upper surface of a reinforcing frame surrounding the semiconductor chip. 5. The semiconductor device according to claim 3, wherein the sub filling resin is hardened by using a mold, and  to an integral surrounding the semiconductor chip Wall. 6. The semiconductor device according to claim 3, wherein the heat expansion coefficient of the underfill resin to one Value between the coefficient of thermal expansion of the substrate and the thermal expansion coefficient of the semiconductor chip is set. 7. The semiconductor device according to claim 3, wherein the sub filling resin from the connection area between the sub strat and the semiconductor chip is removed so that the Fillet only on the periphery of the semiconductor chips is formed. 8. The semiconductor device according to claim 7, wherein a sub filling resin with a lower coefficient of thermal expansion ect in the area from which the underfill resin ent has been removed, is injected. 9. A method of manufacturing a semiconductor device, comprising the following steps:
Mounting a semiconductor chip on a substrate in a flip-chip manner;
Connecting the substrate and the semiconductor chip to one another via a contact bump by melting;
subsequently applying an underfill resin between the substrate and the semiconductor chip, the amount of resin being adjusted so that a fillet formed on one side of the semiconductor chip by applying the underfill resin has a length greater than the distance from the surface of the substrate to the back the semiconductor chip; and
Harden the applied underfill resin. 10. Method for producing a semiconductor device ment according to claim 9, wherein in the step of the order against the underfill resin the fillet on the  Periphery of the semiconductor chip is formed, with the exception the connection area between the substrate and the half conductor chip.